I am married 10 years together 16 with my husband and we have 4 adult children together raging in age 37 - 32.  My son, age 34, is marrying a woman who happens to be a cancer survivor that he's been with 10 years and his step brother & step sister have both been invited.  We did not raise the children together but my son thought it respectful to me and to my husband that they be invited to the wedding. We recently learned that neither are attending citing "work" and that their Dad should understand because he missed much of their childhood citing work.